Switch to C++ to C. Thanks Michael Stilkerich; I never liked C++ anyway.

SunwaitPi.vcxproj

@@ -74,9 +74,9 @@
     <None Include="LICENSE" />
   </ItemGroup>
   <ItemGroup>
-    <ClCompile Include="print.cpp" />
-    <ClCompile Include="sunriset.cpp" />
-    <ClCompile Include="sunwait.cpp" />
+    <ClCompile Include="print.c" />
+    <ClCompile Include="sunriset.c" />
+    <ClCompile Include="sunwait.c" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="print.h" />
@@ -94,4 +94,4 @@
   </ItemDefinitionGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets" />
-</Project>
+</Project>

makefile

@@ -3,19 +3,23 @@
 # 08/12/2014  IFC  0.6  No changes since 0.5
 # 02/05/2015  IFC  0.7  No changes since 0.5, still
 # 10/03/2020  TLJ  0.9  Move headers to fix build on osx
+# 2022-09-16  DRR  0.91 Accept changes from @mstilkerich Michael Stilkerich switches to C from C++
 #
 
-
+CFLAGS=-c -Wall -std=c99 -O2 -Wextra -pedantic
 CXXFLAGS=-c -Wall 
 LDFLAGS= -lm 
-SOURCES=sunwait.cpp sunriset.cpp print.cpp
+SOURCES=sunwait.c sunriset.c print.c
 HEADERS=sunwait.h sunriset.h print.h
-OBJECTS=$(SOURCES:.cpp=.o)
+OBJECTS=$(SOURCES:.c=.o)
 EXECUTABLE=sunwait
-all: $(SOURCES) $(EXECUTABLE)
+all: $(EXECUTABLE)
+
+.c.o:
+	$(CC) $(CFLAGS) $< -o $@
 
 $(EXECUTABLE): $(OBJECTS)
-	$(CXX) $(OBJECTS) -o $@ $(LDFLAGS)
+	$(CC) $(OBJECTS) -o $@ $(LDFLAGS)
 
 clean:
 	rm -f *.o sunwait

openwrt/Makefile

@@ -17,18 +17,18 @@ define Package/sunwait
 	CATEGORY:=Utilities
 	TITLE:=Sunwait
 	URL:=URL:=https://github.com/risacher/sunwait
-	DEPENDS:=+libstdcpp +libc
+	DEPENDS:=+libc
 endef
 
 define Package/sunwait/description
 	Wait until the specified solar event
 endef
 
 define Build/Compile
-	$(TARGET_CC) $(TARGET_CPPFLAGS) -o $(PKG_BUILD_DIR)/sunwait.o -c $(PKG_BUILD_DIR)/sunwait.cpp
-	$(TARGET_CC) $(TARGET_CPPFLAGS) -o $(PKG_BUILD_DIR)/sunriset.o -c $(PKG_BUILD_DIR)/sunriset.cpp
-	$(TARGET_CC) $(TARGET_CPPFLAGS) -o $(PKG_BUILD_DIR)/print.o -c $(PKG_BUILD_DIR)/print.cpp
-	$(TARGET_CC) $(TARGET_LDFLAGS) -o $(PKG_BUILD_DIR)/$1 $(PKG_BUILD_DIR)/sunwait.o $(PKG_BUILD_DIR)/sunriset.o $(PKG_BUILD_DIR)/print.o -lm -lstdc++
+	$(TARGET_CC) $(TARGET_CPPFLAGS) -o $(PKG_BUILD_DIR)/sunwait.o -c $(PKG_BUILD_DIR)/sunwait.c
+	$(TARGET_CC) $(TARGET_CPPFLAGS) -o $(PKG_BUILD_DIR)/sunriset.o -c $(PKG_BUILD_DIR)/sunriset.c
+	$(TARGET_CC) $(TARGET_CPPFLAGS) -o $(PKG_BUILD_DIR)/print.o -c $(PKG_BUILD_DIR)/print.c
+	$(TARGET_CC) $(TARGET_LDFLAGS) -o $(PKG_BUILD_DIR)/$1 $(PKG_BUILD_DIR)/sunwait.o $(PKG_BUILD_DIR)/sunriset.o $(PKG_BUILD_DIR)/print.o -lm
 endef
 
 define Package/sunwait/install

print.cpp → print.c

@@ -1,17 +1,17 @@
 
 /*
-** print.cpp  (of sunwait)
+** print.c  (of sunwait)
 **
 ** Who Ver   When        What
 ** IFC  0.5  04-12-2014  Fix my 1st release of sunwait for windows and port to linux
 ** IFC  0.6  08-12-2014  Add timezone for output of timings
 ** IFC  0.7  30-04-2015  Fix timexone and DST trouble - and problems near dateline
 ** IFC  0.8  2015-05-27  Resolve 'dodgy day' and cleanup
+** DRR  0.91 2022-09-16  Accept change to C from mstilkerich Michael Stilkerich
 **
 */
 
 #include <stdio.h>
-#include <iostream>
 #include <math.h> 
 #include <time.h>
 
@@ -24,17 +24,9 @@ static const char* cComma = ", ";
 
 #define NO_OFFSET 0.0
 
-inline double myDayLength (const double pDouble1, const double pDouble2)
-{ return myAbs (pDouble1 - pDouble2);
-}
-
-inline double myDayLength (const targetStruct *pTarget)
-{ return pTarget->diurnalArc;
-}
-
 // The user-specified offset reduces the diurnal arc, at sunrise AND sunset.
 // But make sure dawn aways is before dusk. The offset can mess that up.
-double diurnalArcWithOffset1 (const double pDiurnalArc, const double pOffset)
+static double diurnalArcWithOffset1 (const double pDiurnalArc, const double pOffset)
 { double arcWithOffset = pDiurnalArc - pOffset - pOffset;
   if (arcWithOffset >= 24.0) return 24.0;
   if (arcWithOffset <=  0.0) return  0.0;
@@ -46,7 +38,7 @@ double diurnalArcWithOffset (const runStruct *pRun, const targetStruct *pTarget)
 }
 
 // What time, in hours UTC, is the offset sunrise?
-double getOffsetRiseHourUTC1 (const double pSouthHourUTC, const double pDiurnalArc, const double pOffsetHour)
+static double getOffsetRiseHourUTC1 (const double pSouthHourUTC, const double pDiurnalArc, const double pOffsetHour)
 { return pSouthHourUTC - diurnalArcWithOffset1 (pDiurnalArc, pOffsetHour)/2.0;
 }
 // Simpler to use form
@@ -55,7 +47,7 @@ double getOffsetRiseHourUTC (const runStruct *pRun, const targetStruct *pTarget)
 }
 
 // What time, in hours UTC, is the offset sunset?
-double getOffsetSetHourUTC1 (const double pSouthHourUTC, const double pDiurnalArc, const double pOffsetHour)
+static double getOffsetSetHourUTC1 (const double pSouthHourUTC, const double pDiurnalArc, const double pOffsetHour)
 { return pSouthHourUTC + diurnalArcWithOffset1 (pDiurnalArc, pOffsetHour)/2.0;
 }
 // Simpler to use form
@@ -64,11 +56,11 @@ double getOffsetSetHourUTC (const runStruct *pRun, const targetStruct *pTarget)
 }
 
 
-void print_a_time
+static void print_a_time
 ( const OnOff   pGmt_OnOff
 , const time_t *pMidnightTimet
 , const double  pEventHour
-) 
+)
 { struct tm tmpTm;
   char tmpBuffer [80];
 
@@ -89,64 +81,42 @@ void print_a_time
   printf ("%s", tmpBuffer);
 }
 
-void print_a_sun_time
+static void print_a_sun_time
 ( const OnOff   pGmt_OnOff
 , const time_t *pMidnightTimet
 , const double  pEventHour
 , const double  pOffsetDiurnalArc
-) 
+)
 { // A positive offset reduces the diurnal arc
   if (pOffsetDiurnalArc <=  0.0 || pOffsetDiurnalArc >= 24.0)
     printf ("--:--");
   else
     print_a_time (pGmt_OnOff, pMidnightTimet, pEventHour);
 }
 
-void print_times
-( const OnOff    pGmt
-, const OnOff    pSunrise
-, const OnOff    pSunset
-, const time_t   pMidnightTimet 
-, const double   pSouthHour
-, const double   pDiurnalArc
-, const double   pOffset
-, const char    *pSeparator
-) 
-{ double offsetDiurnalArc = diurnalArcWithOffset1 (pDiurnalArc, pOffset);
-  double riseHour         = getOffsetRiseHourUTC1 (pSouthHour, pDiurnalArc, pOffset);
-  double setHour          = getOffsetSetHourUTC1  (pSouthHour, pDiurnalArc, pOffset);
+static void print_times
+( const runStruct    *pRun
+, const targetStruct *pTarget
+, const double  pOffsetHour
+, const char   *pSeparator
+)
+{ double offsetDiurnalArc = diurnalArcWithOffset1 (pTarget->diurnalArc, pOffsetHour);
+  double riseHour         = getOffsetRiseHourUTC1 (pTarget->southHourUTC, pTarget->diurnalArc, pOffsetHour);
+  double setHour          = getOffsetSetHourUTC1  (pTarget->southHourUTC, pTarget->diurnalArc, pOffsetHour);
 
-  if (pSunrise == ONOFF_ON)
-    print_a_sun_time (pGmt, &pMidnightTimet, riseHour, offsetDiurnalArc);
-  if (pSunrise == ONOFF_ON && pSunset == ONOFF_ON)
+  if (pRun->reportSunrise == ONOFF_ON)
+    print_a_sun_time (pRun->utc, &pRun->targetTimet, riseHour, offsetDiurnalArc);
+  if (pRun->reportSunrise == ONOFF_ON && pRun->reportSunset == ONOFF_ON)
     printf ("%s", pSeparator);
-  if (pSunset  == ONOFF_ON)
-    print_a_sun_time (pGmt, &pMidnightTimet, setHour, offsetDiurnalArc);
+  if (pRun->reportSunset  == ONOFF_ON)
+    print_a_sun_time (pRun->utc, &pRun->targetTimet, setHour, offsetDiurnalArc);
 
        if (offsetDiurnalArc >= 24.0) printf (" (Midnight sun)");
   else if (offsetDiurnalArc <=  0.0) printf (" (Polar night)");
 
   printf ("\n");
 }
 
-inline void print_times 
-( const runStruct    *pRun
-, const targetStruct *pTarget
-, const double  pOffsetHour
-, const char   *pSeparator
-)
-{ print_times
-  ( pRun->utc
-  , pRun->reportSunrise
-  , pRun->reportSunset
-  , pRun->targetTimet
-  , pTarget->southHourUTC
-  , pTarget->diurnalArc
-  , pOffsetHour
-  , pSeparator
-  );
-}
-
 inline void print_twilight
 ( const double pDayLength
 , const double pTwilightLength
@@ -161,7 +131,7 @@ inline void print_twilight
 void generate_report (const runStruct *pRun)
 {
   /*
-  ** Generate and save sunrise and sunset times for target 
+  ** Generate and save sunrise and sunset times for target
   */
 
   targetStruct tmpTarget;
@@ -173,7 +143,7 @@ void generate_report (const runStruct *pRun)
   double  twilightAngleTarget  = tmpTarget.twilightAngle;
 
   /*
-  ** Now generate the report 
+  ** Now generate the report
   */
 
   struct tm nowTm;
@@ -190,19 +160,19 @@ void generate_report (const runStruct *pRun)
   }
 
   printf ("\n");
-  
+
   strftime (buffer, 80, "%d-%b-%Y %H:%M %Z", &nowTm);
-  printf 
+  printf
   ("      Current Date and Time: %s\n", buffer);
 
   printf ("\n\nTarget Information ...\n\n");
 
-  printf 
+  printf
   ("                   Location: %10.6fN, %10.6fE\n"
   , pRun->latitude
   , pRun->longitude
   );
-  
+
   strftime (buffer, 80, "%d-%b-%Y", &targetTm);
   printf
   ("                       Date: %s\n", buffer);
@@ -231,14 +201,14 @@ void generate_report (const runStruct *pRun)
   else                                                             printf("             Twilight angle: %5.2f degrees (custom angle)\n", twilightAngleTarget);
 
   printf   ("          Day with twilight: "); print_times (pRun, &tmpTarget, NO_OFFSET, cTo);
-  
+
   if (pRun->offsetHour != NO_OFFSET)
   { printf (" Day with twilight & offset: "); print_times (pRun, &tmpTarget, pRun->offsetHour, cTo); }
 
   printf   ("                      It is: %s\n", isDay (pRun) == ONOFF_ON ? "Day (or twilight)" : "Night");
 
   /*
-  ** Generate times for different types of twilight 
+  ** Generate times for different types of twilight
   */
 
   targetStruct daylightTarget;

print.h

@@ -4,6 +4,7 @@
 // 08-12-2014  IFC  0.6  No changes from 0.5
 // 02-05-2015  IFC  0.7  No changes from 0.5, still
 // 2015-05-27  IFC  0.8  Resolve 'dodgy day' and cleanup
+// 2022-09-16  DRR  0.91 Convert to C courtesy mstilkerich 
 //
 
 #ifndef PRINT_H
@@ -12,15 +13,12 @@
 #include "sunwait.h"
 #include "sunriset.h"
 
-void generate_report (const runStruct *pRun);
+void generate_report(const runStruct *pRun);
 
 void print_list (const runStruct *pRun);
 
-double diurnalArcWithOffsetX (const double pDiurnalArc, const double pOffset);
 double diurnalArcWithOffset (const runStruct *pRun, const targetStruct *pTarget);
-double getOffsetRiseHourUTCX (const double pSouthHourUTC, const double pDiurnalArc, const double pOffsetHour);
 double getOffsetRiseHourUTC (const runStruct *pRun, const targetStruct *pTarget);
-double getOffsetSetHourUTCX  (const double pSouthHourUTC, const double pDiurnalArc, const double pOffsetHour);
 double getOffsetSetHourUTC  (const runStruct *pRun, const targetStruct *pTarget);